The
Oldcorollas FAQ
An FAQ dealing with KE1x to KE7x Toyota Corollas
Supplement to http://groups.yahoo.com/groups/oldcorollas
Manifolds
There are several different types of stock exhaust manifold:
Single plane, single outlet
Dual plane, dual outlet
Single plane, single outlet, -C emissions
The single plane manifold is usually fitted to KE1x and 2x from the
factory, it is restrictive and should be the first thing removed when
upgrading the exhaust. The dual plane manifold is quite good, it
separates opposing cylinders and joins them under the passenger
footwell. This comes factory on most KE3x cars. I'd be inclined to
leave this as it is, unless you're hunting for big power. I've
tried and it won't fit on a KE2x, as it hits the steering idler arm,
however this could be remedied with custom dual pipes, they're just
mild steel. The last type of exhaust manifold is just stupid, it joins
the exhaust
flow back into the inlet manifold via a vacuum-actuated thing. Get rid
of that!
All stock exhaust manifolds connect with the intake manifolds at a bolt
triangle. This triangle differs in direction /\ or \/ depending on the
year of the car, it seems KE1x only had the "other" way compared to all
other models. The purpose of this is to heat up the intake manifold so
the fuel atomises better (in theory) and car warms up sooner.
Of course, nothing beats a good set of tuned length extractors. These
range in price from free to $250 new, with the average for second hand
units being $50-$100. Some extractor systems have an extension to the
stock manifold triangle, most don't. Having the inlet manifold not
connected to the exhaust manifold will mean you'll need to add another
5 or so minutes onto your warm-up time.
Pipe size
Don't go any bigger than 2", nuff said. I don't really see any need to
go mandrel bent, but if you can afford it or do it yourself, why not!
It is said a mandrel bent pipe is equivalent to a press bent pipe
quarter of an inch less in size. (ie: 2" press = 1.75" mandrel)
Mufflers
Haven't really done alot of research on this one. My KE35 had a
resonator and a "turbo" style muffler and it wasn't too noisy.
Stewart's KE15 has two resonators and a reverse flow muffler, it is
about the same volume, but that's the motor :) My KE25 has a small
resonator and some sort of huge can and a 4" droop tip, it sounds very
angry, nobody believed it was a stock 3K, now with the 4K I clutch in
whenever I see a cop car.
The more you work a K motor, the deeper and angrier they seem to get. I
don't know why it is, but these are really nice sounding motors!